Alg2 Lesson 3.6: Complex Numbers

Lesson 3.6: Complex Numbers

Obj: I can solve quadratic equations with complex
solutions.

EQ: How do I multiply complex numbers?

Roles:
Facilitator
Scribe
Resourcer
Includer

Lesson Goals:
● Creative Thinking
● Talk through controversies and conflict
● Recognize and reduce ambiguity
● Encourage thinking based on formulas and prior info
● Help explain ideas to each other
● Own your ideas and work
● Record ideas in your journal
● Answer Questions on Slides
● Follow your team roles

Facilitator

• Make sure that all peers are staying on task.

• Give advice or suggestions to resolve the problem.

• Be sure everyone is able to explain.

Scribe

• Make sure peers organize their results on their own papers.

• Remind peers to use color, arrows, and other math tools to
communicate your mathematics, reasons, and connections.

• Be ready to join the teacher for a huddle.

Resourcer

• Make sure peers are getting the materials needed.

• Make sure that all materials are put away neatly.

• Make sure that peers are logged in to the needed site.

• Help troubleshoot any technology difficulties that may arise.

Includer

• Make sure that all peers are talking about their work.

• Helps keep peers’ voice volume low.

• Encourages everyone to ask questions.

• Communicates conflicts or questions to the teacher.

● Check off tasks & skills on calendar.

● Select skills to work on.

● Work on Deltamath.

Remember to work on the following too…

Part 0: Function Operations

Area of a Rectangle

Labelling

Multiply (x + 2)(x² - 7x + 1).

Drag labels to their correct position on the image

2x²

-14x

-7x

+1

x³

-7x²

+2

x²

x

Multiple Choice

Find the product. (x + 2)(x² - 7x + 1).

• x³ - 6x² - 12x + 1
• x³ - 7x² + 2
• x³ - 5x² + 13x + 2
• x³ - 5x² - 13x + 2

Volume of a Rectangular Prism

Part 1: Complex

Expressions

Match

Match each equivalent expression.

• $$i^0$$

• $$i^1$$

• $$i^2$$

• $$i^3$$

1

i

-1

-i

• 1

• i

• -1

• -i

Part 2: Solve Quadratics by

Taking Square Roots

Multiple Choice

Solve for x. 2x² + 50 = 0

• no solution

• x = ±5i
• x = ±5
• x = ±25

Inverses with Restricted Domain

Quadratic Functions
need a restricted
domain for their
inverse to be a
function.

Part 3: Quadratic Formula

Multiple Choice

Solve for x. 𝑥² + 2𝑥 + 13 = 0

• −1 ± 2i√3

• −1 ± 2i
• 1 ± 2i√3
• 1 ± 2√3

Multiple Choice

Solve for x. −2𝑥² + 6𝑥 − 11 = 0

• (6±i√13)/2

• (−2±i√13)/2
• (−1±i√15)/2
• (−3±i√13)/2
• (−4±i√10)/2

Random Question of the Day Time

https://wheelofnames.com/4ke-epz We’ll spin the
wheel as a class and spend a minute or so
discussing our answers.